#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5, sq = 320, INF = 1e6;
int n, m;
vector<int> adj[maxn], radj[maxn];
bool on[maxn];
vector<int> solve() {
int left[n+1];
queue<int> q;
vector<int> ans(n+1);
for (int i=1;i<=n;i++) {
left[i] = adj[i].size();
if (!left[i]) q.push(i);
}
while (q.size()) {
int u = q.front();
q.pop();
if (on[u]) ans[u] = 0;
else ans[u] = -1;
for (int v:adj[u]) if (ans[v] != -1) ans[u] = max(ans[v] + 1, ans[u]);
for (int v:radj[u]) {
left[v]--;
if (!left[v]) q.push(v);
}
}
return ans;
}
vector<int> ori_ans;
vector<pair<int,int>> vec[maxn];
int mn[maxn];
int cnt[maxn];
void pre() {
int left[n+1];
queue<int> q;
for (int i=1;i<=n;i++) {
left[i] = adj[i].size();
if (!left[i]) q.push(i);
}
while (q.size()) {
int u = q.front();
q.pop();
for (int v:radj[u]) {
left[v]--;
if (!left[v]) q.push(v);
}
int sz = adj[u].size();
if (sz == 0) {
vec[u] = {{ori_ans[u] + 1, u}};
continue;
}
for (int v:adj[u]) for (auto [y, x]:vec[v]) mn[x] = INF;
for (int v:adj[u]) for (auto [y, x]:vec[v]) {
mn[x] = min(ori_ans[u] - ori_ans[v] - 1 + y, mn[x]);
}
int pt[sz];
for (int i=0;i<sz;i++) pt[i] = -1;
int l[sz], r[sz];
for (int i=0;i<sz;i++) l[i] = i-1, r[i] = i+1;
int start = 0;
for (int i=1;i<=ori_ans[u] + 1;i++) {
int j = start;
while (j != sz) {
int v = adj[u][j], jsz = vec[v].size();
while (pt[j] + 1 < jsz && mn[vec[v][pt[j]+1].second] <= i) {
pt[j]++;
int x = vec[v][pt[j]].second;
if (cnt[x] == u) continue;
cnt[x] = u;
vec[u].push_back({i, x});
if (vec[u].size() == sq) break;
}
if (vec[u].size() == sq) break;
if (pt[j] == jsz-1) {
r[l[j]] = r[j], l[r[j]] = l[j];
if (j == start) start = r[j];
}
j = r[j];
}
if (vec[u].size() == sq) break;
}
if (vec[u].size() < sq) vec[u].push_back({ori_ans[u] + 1, u});
}
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
int q;
cin >> n >> m >> q;
for (int i=1;i<=m;i++) {
int u, v;
cin >> u >> v;
radj[u].push_back(v); adj[v].push_back(u);
}
for (int i=1;i<=n;i++) on[i] = true;
ori_ans = solve();
pre();
// for (int i=1;i<=n;i++) {
// for (auto [x, y]:vec[i]) cout << x << "." << y << " "; cout << endl;
// }
for (int i=1;i<=n;i++) {
int last = 0;
for (auto [y, x]:vec[i]) {
if (y != last) {
last = y;
assert(solve()[i] == ori_ans[i] - y + 1);
}
on[x] = false;
}
for (auto [y, x]:vec[i]) on[x] = true;
}
while (q--) {
int u, sz;
cin >> u >> sz;
if (!sz) {
cout << ori_ans[u] << "\n";
continue;
}
vector<int> off(sz);
for (int &i:off) {
cin >> i;
on[i] = false;
}
if (sz >= sq) cout << solve()[u] << "\n";
else {
// cout << u << endl;
bool flag = true;
for (auto [y, x]:vec[u]) {
// cout << x << " " << y << endl;
if (on[x]) {
cout << ori_ans[u] - y + 1 << "\n";
flag = false;
break;
}
}
if (flag) cout << "-1\n";
}
for (int i:off) on[i] = true;
}
}
